I will say, as a Dvorak user, I think it would be awful for mobile. I don't know the mathematics for calculating it but Dvorak assumes four fingers per hand spread evenly across the keyboard.

I wonder what the most efficient layout would be for single digit letter pecking. I can imagine it would be different to both Dvorak and Qwerty, but what exactly it would be I don't know. Maybe separating most likely next letters by side and having some consistency of vowels on one side, consonants on the other, but all of the stuff about rolls and sequences would be completely changed. Maybe differently sized buttons for more common letters, or reducing the number of shown letters to have a few flick letters that you swipe in a direction to get them? Maybe just having the top ten most common letters displayed as single buttons and then the remaining 16 as four swipe keys?

gboard and heliboard both have it. been using it for years. it's awful for glide typing since you're mostly just bouncing around the home row.

I gotta say, at first glance it looks terribly inefficient compared to glide typing on even regular QWERTY.